Control device and projection video display device

Abstract

A projection video display device is provided with a projection unit configured to project a video onto a screen via a lens; and an image pickup unit configured to image the screen. A brightness component selection unit receives an image imaged by the image pickup unit when reference light is projected onto the screen and select, of brightness components of pixels forming the image, a brightness component having the maximum value. An exposure correction unit originates a signal for adjusting exposure time in an image pickup device in the image pickup unit with reference to the selected brightness component. A color correction unit receives an image captured by the image pickup unit after the adjustment and corrects the video so that the brightness components are in equal proportion.

1 . A control device provided in a projection video display device having a projection unit for projecting a video onto a screen via a lens, and an image pickup unit for imaging the screen, the control device comprising:
 a brightness component selection unit configured to receive an image imaged by the image pickup unit when reference light is projected onto the screen and select, of brightness components of pixels forming the image, a brightness component having the maximum value;   an exposure correction unit configured to originate a signal for adjusting exposure time in an image pickup device in the image pickup unit with reference to the selected brightness component; and   a color correction unit configured to receive an image captured by the image pickup unit after the adjustment and correct the video so that the brightness components are in equal proportion.   
     
     
         2 . The control device according to  claim 1 , further comprising:
 a screen frame detection unit configured to detect a screen frame from the image captured by the image pickup unit,   wherein the brightness component selection unit selects the brightness component having the maximum value only within the detected screen frame.   
     
     
         3 . A projection video display device comprising:
 a projection unit configured to project a video onto a screen via a lens;   an image pickup unit configured to image the screen; and   the control device according to  claim 1 .   
     
     
         4 . A control device provided in a projection video display device having a projection unit for projecting a video onto a screen via a lens, and an image pickup unit for imaging the screen, the control device comprising:
 a brightness component selection unit configured to receive an image imaged by the image pickup unit when reference light is projected onto the screen and select, of brightness components of pixels forming the image, a brightness component having the maximum value; and   an exposure correction unit configured to correct the reference light so that the brightness components are in equal proportion with reference to the selected brightness component.   
     
     
         5 . The control device according to  claim 4 , further comprising:
 a screen frame detection unit configured to detect a screen frame from the image captured by the image pickup unit,   wherein the brightness component selection unit selects the brightness component having the maximum value only within the detected screen frame.   
     
     
         6 . A projection video display device comprising:
 a projection unit configured to project a video onto a screen via a lens;   an image pickup unit configured to image the screen; and   the control device according to  claim 4 .